1. Field of the Invention
My invention relates to tools and methods for repairing seams in certain types of sheet materials. More particularly, my invention relates to repairing seams in pliable sheet materials that are used as functional and decorative surface coverings, such as linoleum or vinyl floor coverings. Such materials are adhered to the surface (usually a floor) that is to be covered. Butt seams are used to join separate pieces of such materials when the desired area cannot be covered by a single piece. Hereinafter, I use the term xe2x80x9csheet materialsxe2x80x9d to refer only to pliable sheets of materials that are relatively smooth on both major surfaces, such as sheets of vinyl and other polymeric materials, and laminates thereof. I use xe2x80x9cfloor coveringsxe2x80x9d to refer only to such sheet materials that are used to cover floors, excluding rigid flooring such as wooden laminates or ceramic tiles, and excluding textiles such as carpeting.
2. Description of the Related Art
When abutting pieces of floor covering are seamed together and glued in place, the seam will often degrade over time because of exposure to traffic, moisture, cleaning chemicals, and dirt. Contamination will eventually penetrate the seam and degrade the adhesive holding the floor covering to the floor at the seam. When the adhesive becomes degraded, the floor covering will lift from the floor at the seam, lending the seam an unsightly puckered appearance and making the seam more vulnerable to further damage. In order to repair the damaged portion of the seam, it is usually necessary to carefully cut out and replace it with a fresh patch of matching material. The patch must match the removed portion""s pattern and shape perfectly, or the repair will be visible.
Currently, no tools like my invention are available for repairing seams in floor covering materials. A craftsperson must make do with conventional cutting tools, such as construction knives and straight edges to accomplish the precision repair job required. It is very difficult to exactly match the shape and decorative pattern of the patch to that of the removed portion. It is especially difficult to exactly match the edge surfaces of the patch to the edge of the removed portion so that the resulting butt seam will be as good as the original. To make a perfect seam, a craftsperson must cut the patch to exactly match the removed portion not only in the two-dimensional geometry of the floor, but also along the third dimension defined by the sheet thickness along its edge. A mismatch in any dimension will create a weakness or visible imperfection along the edges of the patch. Consequently, only the most skilled craftspeople are able to repair the seam so that the patch is both invisible and durable, and only by the exercise of great care.
Various double-bladed knifes, scalpels, and cutting tools exist for cutting various materials, and some of these double-bladed tools may be capable of cutting floor coverings. However, no existing tool is adapted for repairing damaged seams in floor coverings like my device, and no method like my method has been developed before.
Thus, a need exists for way to repair damaged seams in floor coverings that is easier to use than present methods, and consistently achieves a perfect repair that is invisible and durable. It is further desirable that any tool used for the repair be rugged, reliable, easy to operate, and relatively inexpensive so that it may be used by professional craftspeople and amateurs alike.
The chief object and advantage of my invention are to make it much easier and faster than present methods to perfectly repair a damaged seam in floor coverings. Craftspeople and amateur repair people of many different skill levels and abilities are able to competently repair a seam using my tool and method. My invention consists of a hand held precision cutting tool and a method for using the tool to repair a seam. I have designed the tool to be inexpensive to construct, rugged, reliable, and easy to operate. The method for using it consists of a limited number of steps that are easy to teach, easy to learn, and easy to do. My repair procedure can also be performed much more quickly than current methods. Thus, my invention will be of value to anyone who needs to repair seams in sheet materials, and especially floor coverings.
My repair tool is essentially a specially designed double-bladed precision knife with adjustable blades. The dual blades are nearly parallel but are inclined slightly to make a cut that is beveled slightly away from the centerline of the tool, to undercut the material being repaired. Each blade is a rigid precision blade and is securely fixed to the body of the tool near each blade""s working edge. Thus the cutting blades are more stable than blades in conventional utility knives and are capable of making precision cuts. The distance between the blades is adjustable by means of a fine pitch adjustment screw attached to a thumbwheel. The adjustment screw is back loaded to remove adjustment slop and prevent unintentional movement of the screw.
To use my repair tool, an operator sets the distance between the blades to just slightly wider than the widest portion of the damaged seam to be removed. The operator then draws my tool along the seam with the blades straddling the seam, while applying downward cutting pressure. The operator then removes the material between the parallel cuts, and cleans out the resulting groove. Then, from a piece of scrap material that matches the pattern of the removed material, the operator cuts a strip of the same length and pattern as the removed material. This will serve as the repair strip. However, before cutting the repair strip, the operator adjusts the blades of the knife to be slightly wider apart than when cutting out the damaged portion of the seam. This ensures that the repair strip will fit snugly into the groove previously cut in the material to be repaired. The operator then applies a small amount of flooring adhesive along the bottom of the groove and, using a roller, presses the repair strip in place along the groove. The matching bevels of the repair strip and the groove help to lock the repair strip in place. Furthermore, the edges of the repair piece match the groove perfectly and are uniformly snug along the length of the patch. Thus, the repair strip is held firmly in place with its edges as good or better than the original seam. To complete the repair, the operator applies a conventional seam sealing adhesive to seal the patch and protect it from contamination.